Design Rationale for Cushion Timer and Logger

Transcription

1 Design Rationale for Cushion Timer and Logger Laura came up with the original idea. She was inspired by concerns about health and the amount of time people spend at their desks each day. We decided to adapt a cushion with a force sensor so that it could tell when a person had sat for a certain length of time and then play an irritating tune to inspire the person to stand and move around. Due to the limited amount of time, we choose to hack an existing cushion of the desired size and appropriate padding rather than make our own cushion. We selected one that was sturdy enough to keep the sitter from feeling the components, large enough to provide space for the components, and pretty enough to not offend the eyes. We purchased this cushion (a cushion meant for outdoor furniture) at Bed, Bath and Beyond, keeping in mind the price and availability. We created our project with an Arduino as it affords the ability to run a program based on the information from a force resistor. We wanted to be able to control what the reaction was. As we developed the project and discussed it with Professor Barba, we tentatively decided to incorporate a data logging shield. This affords the ability to time stamp when certain defined actions occur. For us, those actions were when the force sensor senses sitting or standing, defined by whether the resistance was above or below a threshold. The data logging shield writes the requested information on an SD card, and when the SD card is plugged into a computer, the user can export the data to a spreadsheet (See our appendix for examples). Ideally, we would give the cushion to a subject and he or she would sit on it for about a week with the sitting and standing changes time stamped and logged, but without the tune activated. Then, we would activate the timer program to play the tune, with a reasonable time delay. At the moment, our prototype will not sense a stand and then re-sit during the timed delay period that is something we want to address in any future iteration. The sound that plays after the delay has gone through multiple iterations a single tone, then a melody that wasn t irritating, and now the melody from It s a Small World (commonly recognized as irritating). Due to the nature of the tune code we adapted, the tune currently plays 2.5 rounds and does not stop immediately upon a person standing. We think that this is still short enough to not cause many annoyance problems with co-workers. If the person does not stand, the tune will continue to play until he or she does stand. To create the programming, we included codes from Arduino s Tone 3 code, a Melody code, Print.screenIn code from the adafruit programming, and incorporated a threshold variable and a count delay. Together, the code forms a program that accomplishes our purpose. While this is a rough prototype, it is a step towards tracking personal health information in an area that has not previously been tracked (we could not find a comparable chair or cushion). It allows for the gathering of data about current habits and the shaping of these habits. Emily 360 reflection: I believe Laura and I split the responsibilities of the final project relatively successfully. We worked well together, dividing up the project into manageable portions and, as we finalized a portion, adding new elements which increased the complexity of the final project. We each brought certain strengths to the project and focused on specific aspects. I focused on some initial

2 research and then identifying components as we needed them. I hacked the housing of our project: the cushion. I soldered wire and some components, cut and resewed, and adapted the cushion s opening and inside to hold a plastic container, which protected our circuitry. I took videos and photos (always less than I thought!) and wrote preliminary drafts of our blogs and documents for Laura to improve. We tried to work together as much as possible so that we so that we could troubleshoot and test together, and help each other with problems. I am very aware, through this project, of the importance of knowing code. If I had not worked with Laura, I would have been lost as our project ended up requiring a lot of alterations and combinations of existing codes and then the addition of some entirely new elements. I had initially thought that we would be able to combine a couple of codes easily, which did not turn out to be the case. I wish I had taken a coding class at CCT and now plan to rectify that omission independently post graduation. In general, I really enjoyed putting together circuits following the diagrams and wish that we had had more time to spend on trying a variety of circuits. Finally, I wish the class could have lasted longer and delved even deeper into the three main areas. Laura s Reflection It is always easy to work with Emily because we both want to turn in good projects. It makes it easier to divide project tasks. We both did initial research for the codes we would need. Emily found a melody specific code, whereas I was able to find the codes need for the force resistor and threshold. I also did a lot of the research for products similar to what we wanted to create. It was really interesting to find that nothing like it is on the market. The closest item we found was something Stevie knew about, which was a car seat that can tell who is sitting in it based on pressure and sitting patterns. Emily was the one that found the adafruit data logger. Together we went through its instructions to figure out how to connect it to the Arduino. Since I have some understanding of code, and Emily very little experience, I did most of the coding (with, of course, lots of assistance from Professor Barba). One of my mistakes was trusting that the codes we found would work properly. We tried using one for our data logging aspect that would not compile. I sent half an hour trying to see what I had done wrong, until we finally checked the code by itself and discovered that it did not work at all. I may not know the Arduino code very well, but I should have trusted my instincts a bit better and not assumed I was placing the code elements in the wrong place. One thing that I think would have been helpful, instead of simply building the circuits when we were first introduced to the Arduino, is going over some of the basic Arduino codes. I was able to find the dictionary for the codes, but only after about a week and half. Going over some of that as a class I think would have helped Emily and I understand some of the pre-written codes better. Emily was able to take care of our sewing needs, which was very helpful since I have no idea how to sew. We tried to break the rest of the tasks evenly. When we soldered, we were both present and switched off so we both added to the final data logging aspect. We both enjoyed soldering and found that we did much better after Professor Barba took a look at our first attempt. Maybe turning in the projects along the way and getting feedback (not grades!) would be beneficial. We could have known some of our first solder was bad.

3 Appendix Video: Code: const int threshold = 250; // minimum reading of the sensors that generates a note bool Sitting =false; #include <SPI.h> #include <SD.h> #include <Wire.h> #include "RTClib.h" RTC_DS1307 rtc; File myfile; const int chipselect = 10; // TONES ========================================== // Start by defining the relationship between // note, period, & frequency. #define c 3830 // 261 Hz #define d 3400 // 294 Hz #define e 3038 // 329 Hz #define f 2864 // 349 Hz #define g 2550 // 392 Hz #define a 2272 // 440 Hz #define b 2028 // 493 Hz #define C 1912 // 523 Hz // Define a special note, 'R', to represent a rest #define R 0 // SETUP ============================================ // Set up speaker on a PWM pin (digital 9, 10 or 11) int speakerout = 8; // Do we want debugging on serial out? 1 for yes, 0 for no int DEBUG = 1; void setup() { pinmode(speakerout, OUTPUT); /* if (DEBUG) { Serial.begin(9600); // Set serial out if we want debugging */

4 { Serial.begin(9600); Serial.print("Initializing SD card..."); // On the Ethernet Shield, CS is pin 4. It's set as an output by default. // Note that even if it's not used as the CS pin, the hardware SS pin // (10 on most Arduino boards, 53 on the Mega) must be left as an output // or the SD library functions will not work. pinmode(10, OUTPUT); if (!SD.begin(chipSelect)) { Serial.println("initialization failed!"); return; Serial.println("initialization done."); // open the file. note that only one file can be open at a time, // so you have to close this one before opening another. myfile = SD.open("logfile3.csv", FILE_WRITE); // if the file opened okay, write to it: if (myfile) { Serial.print("Writing to logfile3.csv..."); // close the file: myfile.close(); Serial.println("done."); else { // if the file didn't open, print an error: Serial.println("error opening logfile3.csv"); /* // re-open the file for reading: myfile = SD.open("test3.csv"); if (myfile) { Serial.println("test3.csv:"); // read from the file until there's nothing else in it: while (myfile.available()) { Serial.write(myFile.read()); // close the file: myfile.close(); else { // if the file didn't open, print an error: Serial.println("error opening test3.csv"); */

5 //Serial.begin(9600); #ifdef AVR Wire.begin(); #else Wire1.begin(); // Shield I2C pins connect to alt I2C bus on Arduino Due #endif rtc.begin(); if (! rtc.isrunning()) { Serial.println("RTC is NOT running!"); // following line sets the RTC to the date & time this sketch was compiled rtc.adjust(datetime( DATE, TIME )); //end setup // MELODY and TIMING ======================================= // melody[] is an array of notes, accompanied by beats[], // which sets each note's relative length (higher #, longer note) int melody[] = { g, g, b, g, a, a, a, a, R, g, g, b, g, a, a, a, a ; int beats[] = { 24, 8, 16, 16, 24, 8, 24, 8, 24, 8, 16, 16, 24, 8, 24 ; int MAX_COUNT = sizeof(melody) / 2.5; // Melody length, for looping. // Set overall tempo long tempo = 20000; // Set length of pause between notes int pause = 1000; // Loop variable to increase Rest length int rest_count = 100; //<-BLETCHEROUS HACK; See NOTES // Initialize core variables int tone_ = 0; int beat = 0; long duration = 0; // PLAY TONE ============================================== // Pulse the speaker to play a tone for a particular duration void playtone() { long elapsed_time = 0; if (tone_ > 0) { // if this isn't a Rest beat, while the tone has // played less long than 'duration', pulse speaker HIGH and LOW while (elapsed_time < duration) { digitalwrite(speakerout,high); delaymicroseconds(tone_ / 2);

6 // DOWN digitalwrite(speakerout, LOW); delaymicroseconds(tone_ / 2); // Keep track of how long we pulsed elapsed_time += (tone_); else { // Rest beat; loop times delay for (int j = 0; j < rest_count; j++) { // See NOTE on rest_count delaymicroseconds(duration); void loop() { DateTime now = rtc.now(); // get a sensor reading: int sensorreading = analogread(a0); //Serial.println(sensorReading); // Serial.println("Standing reading = "); // if the sensor is pressed hard enough: if (sensorreading > threshold) { now = rtc.now(); Serial.println(sensorReading); Serial.println(" - Sitting"); if (Sitting == false) { // open the file. note that only one file can be open at a time, // so you have to close this one before opening another. myfile = SD.open("logfile3.csv", FILE_WRITE); // if the file opened okay, write to it: if (myfile) { Serial.print("Writing to logfile3.csv..."); myfile.print("sitting "); now = rtc.now(); myfile.print(now.year(), DEC); myfile.print('/'); myfile.print(now.month(), DEC); myfile.print('/'); myfile.print(now.day(), DEC); myfile.print(' ');

7 myfile.print(now.hour(), DEC); myfile.print(':'); myfile.print(now.minute(), DEC); myfile.print(':'); myfile.print(now.second(), DEC); myfile.println(' '); // close the file: myfile.close(); Serial.println("done."); else { // if the file didn't open, print an error: Serial.println("error opening logfile3.csv Two"); delay (3000); while(sitting == false) { // Set up a counter to pull from melody[] and beats[] for (int i=0; i<max_count; i++) { tone_ = melody[i]; beat = beats[i]; duration = beat * tempo; // Set up timing playtone(); //Serial.println(sensorReading); // A pause between notes... delaymicroseconds(pause); //Serial.println(sensorReading); if (sensorreading < threshold) { Sitting = true; sensorreading = analogread(a0); if (sensorreading < threshold) { Serial.println(sensorReading); Serial.println(" - Standing"); now = rtc.now(); if (Sitting == true) { Sitting = false; // open the file. note that only one file can be open at a time, // so you have to close this one before opening another.

8 myfile = SD.open("logfile3.csv", FILE_WRITE); // if the file opened okay, write to it: if (myfile) { Serial.print("Writing to logfile3.csv..."); myfile.print("standing "); now = rtc.now(); myfile.print(now.year(), DEC); myfile.print('/'); myfile.print(now.month(), DEC); myfile.print('/'); myfile.print(now.day(), DEC); myfile.print(' '); myfile.print(now.hour(), DEC); myfile.print(':'); myfile.print(now.minute(), DEC); myfile.print(':'); myfile.print(now.second(), DEC); myfile.println(' '); // close the file: myfile.close(); Serial.println("done."); else { // if the file didn't open, print an error: Serial.println("error opening logfile3.csv three"); notone(8); //endif //endif sitting false //endif sensor reading //endloop

9 Data: Serial Monitor

10 Text File

11 Exported Data * Please note that this is not all the data collected by the cushion. When we went to export the data from our SD card we realized that we had wrote the code so that each point of data was on its own line. This means that our data would not import easily into Excel. Laura had to go through force them on to one line, so we cut some data to simply the process. Laura then fixed the code so that relevant information was on the same line, separated by a space. Below are examples of this change.

12 Data File

13 Exported Data